Thanks for writing. What you're seeing sound like fungus gnats, very common insects. They thrive in moist soil, so letting your indoor plants dry out a little more between waterings should help stop the pests. I've also heard some folks have good success by putting an inch or two of sand over the surface of their potting soil. This creates a dry barrier that the gnats can't lay their eggs in.
Otherwise, there's a natural product called Knock-Out Gnats that may work. It is a bacterium that only affects the gnats. Learn more here.
---Justin, Senior Garden Editor, BHG.com